Contact lenses are currently worn by a large number of users in lieu of glasses, as a means for improving the vision of the users. A contact lens is a corrective, cosmetic or therapeutic lens that is usually on the cornea of the eye. Modern contact lenses were invented by Otto Wichterle sometime around 1961.
Contact lenses serve the same corrective purpose as conventional glasses. Modern contact lenses are light weight and virtually invisible, although some contact lenses are tinted to make them more visible when being cleaned, and other lenses are deliberately colored for altering the appearance of the eye. It has been estimated that about 125 million people use contact lenses worldwide.
Although contact lenses are believed by many to represent a great improvement over eye glasses, room for improvement exists. One area in which room for improvement exists is to create contact lenses that are capable of use in water environments. These environments include the environments that one would encounter as a swimmer, scuba diver, or snorkler. To address these concerns, the Applicant Michael H. Fritsch invented an underwater contact lens that is disclosed in U.S. Pat. No. 5,831,713 (issued 3 Nov. 1998) and U.S. Pat. No. 6,048,063 (issued 11 Apr. 2000). The underwater contact lens disclosed and claimed by Dr. Fritsch in these two patents provided an underwater correction of vision, while providing a contour that enabled the contact lens to be held onto the cornea of the eye. In one embodiment of the inventions, the lens provides a corrective ability useable for both underwater and out-of-water uses.
Although the devices disclosed in the two Fritsch patents described above performed their intended functions in a workmanlike manner, room for improvement still exists. In particular, room for improvement exists in providing an underwater contact lens that incorporates improved features, such as an ability to resist trapping microbes on the eye surface covered by the lens, to thereby reduce the likelihood of microbial infection of the eye of the user.
Since the water in which the user is submerged while wearing the lens is not sterile, the water in which the user is swimming is a source for possible microbial seeding of the eye. Additionally, since the lens is separate from the human body, the lens has the potential to act as a foreign body fomite for entrapping and harboring microbes. Finally, one problem with the lens is that the fact that since the lens covers a cornea, the lens prevents normal eye lid blinking to cleansingly sweep the corneal eye surface of debris and microbes.
As is well known to contact lens wearers, one adverse side effect of wearing contact lenses is the potential for in eye infections. With air usage contact lenses, infection is avoided by regular cleaning of the lenses, limiting the wearing time of the lenses to finite time periods, and resting the eye between applications of the contact lens. Additionally, air-worn contact lenses have an advantage over water-worn contact lenses since air-worn contacts do not suffer the constant onslaught of microbes or impurities that attack the eye in a water-worn situation.
It is therefore one object of the present invention to provide a contact lens that is capable of being worn for extended time periods in a water environment, and that will include improvements over known contact lenses.